Effect of magnesium sulfate on anesthesia depth, awareness incidence, and postoperative pain scores in obstetric patients. A double-blind randomized controlled trial.

Objectives: To assess the effects of magnesium on the depth of anesthesia and to determine the effects of magnesium on incidence of awareness and postoperative pain after caesarean section.  Methods: The study was designed as a double-blind, controlled, randomized study and conducted in Hacettepe University Hospital, Ankara, Turkey  between January 2015 and March 2016. A total of 100 pregnant healthy women who were between 17 and 41 years old, ASA II, and scheduled for an elective cesarean section with general anesthesia were included in the study. After induction, sevoflurane was used for maintenance in Group S and desflurane in Group D (control groups). At Group S-M and Group D-M (study groups), magnesium infusion was started with sevoflurane and desflurane anesthesia respectively. Minimum alveolar concentration of sevoflurane and desflurane were kept constant. Bispectral index scores (BIS), fentanyl consumption and postoperative visual analogue scale (VAS) values were recorded. All of the patients had been followed-up for awareness until the postoperative first year. Results: Demographic variables of the patients were similar. BIS values were significantly higher in control groups throughout the operation (p less than 0.001). No significant difference was detected for intraoperative fentanyl consumption and awareness incidence. VAS values were significantly lower in study groups (p less than 0.05). Conclusion: Magnesium infusion provided significantly lower intraoperative BIS values and lower postoperative VAS scores. We believe that magnesium can be useful as an adjuvant to general anesthesia.